Insights into the characteristics and sources of primary and secondary organic carbon: High time resolution observation in urban Shanghai

Jian Xu; Qiongzhen Wang; Congrui Deng; V Faye McNeill; Alison Fankhauser; Fengwen Wang; Xianjue Zheng; Jiandong Shen; Kan Huang; Guoshun Zhuang

doi:10.1016/j.envpol.2017.10.003

Insights into the characteristics and sources of primary and secondary organic carbon: High time resolution observation in urban Shanghai

Environ Pollut. 2018 Feb:233:1177-1187. doi: 10.1016/j.envpol.2017.10.003. Epub 2017 Oct 14.

Authors

Jian Xu¹, Qiongzhen Wang², Congrui Deng³, V Faye McNeill⁴, Alison Fankhauser⁴, Fengwen Wang⁵, Xianjue Zheng⁶, Jiandong Shen⁶, Kan Huang⁷, Guoshun Zhuang⁸

Affiliations

¹ Center for Atmospheric Chemistry Study, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
² Center for Atmospheric Chemistry Study, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Environmental Science Research & Design Institute of Zhejiang Province, Hangzhou, Zhejiang 310007, China.
³ Center for Atmospheric Chemistry Study, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
⁴ Department of Chemical Engineering, Columbia University, New York, NY 10027, USA.
⁵ Department of Environmental Science, College of Resources and Environmental Science, Chongqing University, Chongqing 400030, China.
⁶ Hangzhou Environmental Monitoring Center, Hangzhou, Zhejiang 310007, China.
⁷ Center for Atmospheric Chemistry Study, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China. Electronic address: huangkan@fudan.edu.cn.
⁸ Center for Atmospheric Chemistry Study, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China. Electronic address: gzhuang@fudan.edu.cn.

PMID: 29037494
DOI: 10.1016/j.envpol.2017.10.003

Abstract

There is growing evidence suggesting that organic aerosols play an important role in the evolution of severe haze episodes. However, long-term investigations of the different characteristics of carbonaceous aerosols during haze and non-haze days are insufficient. In this work, hourly measurements of organic carbon (OC) and elemental carbon (EC) in PM_2.5 were conducted in Shanghai, a megacity in Eastern China, over the course of a year from July 2013 to June 2014. Both OC and EC exhibited a bimodal diel pattern and were highly dependent on the wind speed and direction. The concentration-weighted trajectory (CWT) analysis illustrated that primary OC (POC) and EC were largely associated with regional and long-range transport. Secondary OC (SOC) formation was the strongest during the harvest season owing to significant biomass burning emissions from the adjacent Yangtze River Delta and farther agricultural regions. Compared to OC (6.7 μg m^-3) and EC (2.0 μg m^-3) in the non-haze days, higher levels of both OC (15.6 μg m^-3) and EC (7.7 μg m^-3) were observed in the haze days as expected, but with lower OC/EC ratios in the haze days (2.4) than in non-haze days (4.6). The proportion of POC and EC in PM_2.5 remained relatively constant as a function of PM_2.5 mass loadings, while that of SOC significantly decreased on the highly polluted days. It is concluded that the haze pollution in urban Shanghai was influenced more by the primary emissions (POC and EC), while the role of SOC in triggering haze was limited.

Keywords: Biomass burning; Carbonaceous aerosol; Haze; PM(2.5); SOC.

MeSH terms

Aerosols / analysis
Air Pollutants / analysis*
Biomass
Carbon / analysis*
China
Environmental Monitoring*
Particle Size
Particulate Matter / analysis
Rivers
Seasons
Wind

Substances

Aerosols
Air Pollutants
Particulate Matter
Carbon